Word: 断定 (duàndìng) Traditional: 斷定 断定 dictionary entry duàndìng to conclude; to determine; to come to a judgment Full dictionary entry for 断定 Example sentences using 断定 2 sentences, showing page 1 of 1. 你凭什么断定这件事是他做的？ Nǐ píng shénme duàndìng zhè jiàn shì shì tā zuò de? On what basis do you conclude that he did this? 看他的表情，我断定他没说实话。 Kàn tā de biǎoqíng, wǒ duàndìng tā méi shuōshíhuà. Judging by his expression, I concluded he wasn't telling the truth.